基于吩嗪衍生物的荧光增强型氰离子探针

针对氰根离子的强亲核反应性,设计并合成了一种以吩嗪为荧光团,吲哚磺酸作为吸电子基团和识别基团的反应型化学传感器PDSI。研究表明,具有强给电子能力的吩嗪和带正电荷的拉电子吲哚双键表现出很强的分子内电荷转移(ICT),当加入氰根离子后,由于双键被破坏,吲哚基团上氮原子的正电荷被中和,吸电子能力迅速降低,750nm处的ICT吸收带吸光度相应下降,肉眼可明显观察到溶液体系的颜色由绿色逐渐变为淡黄色,实现了对氰根离子直观的颜色响应;同时吩嗪荧光团荧光恢复,在580nm左右表现出20倍荧光增强;此外,化合物PDSI具有良好的选择性,其它阴离子对体系的吸收和荧光没有明显影响。PDSI对氰根离子的检出限达到0.02μmol/L,低于世界卫生组织及美国环保局规定的饮用水中氰化物含量上限0.02ppm。     

一种双波长激发型香豆素pH荧光探针及其识别机理研究

本项工作以7-羟基香豆素荧光团为原料,构建了一种双波长激发型pH值荧光探针CpH.该探针的pKa值为6.06,其线性检测范围为4.0～7.4,而且还具有光稳定性强、灵敏度高、选择性高和可逆性好等优点.     

基于半花菁染料荧光探针的应用及研究进展

半花菁是一个氮杂环阳离子和一个末端羟基、烷氧基或氨基通过π共轭桥连在一起的荧光染料,具有优异的光学性质和良好的稳定性,其独特的线粒体靶向能力以及近红外发射特性使以半花菁为骨架的荧光探针在荧光检测和识别方面发挥着重要的作用.本文综述了基于半花菁染料构建的荧光探针在识别各种离子、活性硫、生物酶等方面的研究及应用.     

一种基于次氯酸根离子的比率型荧光探针及其应用

以2-苯并噻唑-5-甲基苯酚为原料,合成了一种基于次氯酸根离子的比率型荧光探针ZN1,并对其进行了次氯酸根离子的检测性能测试。结果表明:该探针可以快速灵敏、选择性地识别次氯酸根离子,其检测下限为0.96μmol/L,并将该探针应用于实际水样中次氯酸根离子含量的检测,在自来水、雨水中的回收率均大于84%。此外,利用质谱和核磁谱图开展的检测机理研究表明,探针的识别机理与次氯酸的氧化脱氢作用和激发态分子内质子转移(ESIPT)过程破坏有关。     

基于二氟化硼-二吡咯甲烷(BODIPY)染料类汞离子荧光探针的研究进展

Hg2+是一种极具生理毒性的化学物质,对人类和环境危害极大,其检测方法在化学传感器领域得到广泛研究。荧光探针法因具有检测灵敏度高、快速便捷等优点而成为Hg2+检测的重要手段之一。综述了近年来BODIPY类染料汞离子的研究进展,着重总结了Hg2+荧光探针的设计合成、性能及其检测机制;展望了该类荧光探针的研究方向。     

一种ICT型荧光探针的光谱性质与识别机制研究

以经典的金属离子响应型多羧酸识别基团为结构基础,连接苯乙烯类发色团苯并咪唑荧光基团,在识别基团与荧光基团之间构筑分子内电荷转移(ICT)机制,合成得到一种荧光探针T13;通过荧光光谱、紫外吸收光谱等手段,初步阐明了探针T13对Zn²⁺、Cu²⁺、Hg²⁺的识别机制。结果表明,探针T13对目标物Zn²⁺、Cu²⁺、Hg²⁺均表现出特征响应与稳定荧光性能;识别过程中荧光强度与目标物浓度线性相关,探针与目标物的络合比为1∶1,能够用于水环境中Zn²⁺、Cu²⁺、Hg²⁺的定性检测和定量分析。为探针结构优化、性能筛选与探针-目标离子的生物学成像研究提供了理论基础。     

一种基于DNA G-四链体结构的汞离子快速检测方法

随着工业的发展汞污染日渐严重,建立一种快速、准确的Hg²⁺检测手段变得更加重要。某些富鸟嘌呤(G)的核酸序列能够通过氢键和自身链或者其他序列链上的鸟嘌呤(G)连接折叠成为四链结构,称为G-四链体。Hg²⁺可以和G-四链体中的胸腺嘧啶T相互作用形成T-Hg²⁺-T结构,G-四链体也会形成DNA双链结构,这种变化可以影响菁染料的聚集状态,进而引起溶液紫外-可见吸收光谱的变化。基于DNA G-四链体转化菁染料聚集状态开发了一种Hg²⁺检测手段。     

一种基于苯基噌啉类铱配合物的新型汞离子探针

以3,4-二苯基噌啉为环金属配体,6,7-二氰基二吡啶并喹喔啉为解离配体合成了一种新型环金属铱配合物.配合物的结构通过红外、质谱、核磁进行了表征.配合物的最大发射波长为603 nm,磷光寿命为1.17 μs.在与金属阳离子的作用中,该配合物表现出了对Hg2+的选择性磷光淬灭性能,能作为Hg2+的磷光探针.     

一种基于ESIPT原理的反应型半胱氨酸荧光探针的合成及细胞成像研究

本研究基于分子内质子转移机制(ESIPT),制备了一种具有选择性识别Cys的反应型荧光探针(探针1)。在乙腈-磷酸盐缓冲溶液(3:7,体积比,pH 7.4)中,探针1的荧光强度与Cys的浓度在10～100μmol/L范围内呈现良好的线性关系(y=4.127x+42.84, R²=0.9978),检测限为36.7 nmol/L。该探针对Cys的响应具有较大的Stokes位移(160 nm)、高灵敏度和选择性。此外,探针1还具有良好的细胞膜通透性和生物相容性,可用于A549细胞中Cys的荧光成像,在生物分析中具有潜在的应用价值。     

双探头传感器可燃气体报警器的设计

针对目前国内常用的可燃气体报警器的检测原理及结构设计的现状,结合可燃气体报警器在检定周期内存在安全隐患及缺陷的弊端,详细分析了催化燃烧型、双波长红外型传感器的原理和应用环境的优势,最终将两种传感器的优势相融合,提出双探头传感器可燃气体报警器的设计方案。该方案结合了催化燃烧型、双波长红外型两种传感器的优点,既可以检测出所有可燃气体,又可以检测出含硫、硅、磷等元素的气体,避免了双探头传感器因其中一个传感器失灵而引起的报警器失效,大大提高了安全系数。     

A benzothiazole-based semisquarylium dye suitable for highly selective Hg sensing in aqueous media

A novel semisquarylium dye was synthesized by the reaction between 3,4-dibutoxy-3-cyclobutene-1,2-dione and a benzothiazolium salt and its metal ion sensing properties were investigated using absorption and emission spectroscopy. These misquarylium exhibited high selectivity for Hg²⁺ ions, as compared with Ca²⁺, Pb²⁺, Al³⁺, Ce²⁺, Ba²⁺, Ni²⁺, Cd²⁺, Zn²⁺ and Mg²⁺ ions in DMSO/H₂O (9:1, v/v), which was attributed to the formation of a 2:1 BSQ:Hg²⁺ coordination complex, the formation of which was supported by the calculated geometry of the complex.     

A highly selective fluorescent probe for real-time imaging of UDP-glucuronosyltransferase 1A8 in living cells and tissues

Uridine diphosphate(UDP)-glucuronosyltransferases(UGTs)are enzymes involved in the biotransformation of important endogenous compounds such as steroids,bile acids,and hormones as well as exogenous substances including drugs,environmental toxicants,and carcinogens.Here,a novel fluorescent probe BDMP was developed based on boron-dipyrromethene(BODIPY)with high sensitivity for the detection of UGT1A8.The glucuronidation of BDMP not only exhibited a redemission wavelength(lex/lem=500/580 nm),but also displayed an excellent UGT1A8-dependent fluorescence signal with a good linear relationship with UGT1A8 concentration.Based on this perfect biocompatibility and cell permeability,BDMP was successfully used to image endogenous UGT1A8 in human cancer cell lines(LoVo and HCT15)in real time.In addition,BDMP could also be used to visualize UGT1A8 in tumor tissues.These results suggested that BDMP is a promising molecular tool for the investigation of UGT1A8-mediated physiological function in humans.     

A highly selective chemosensor for Cu and Al in two different ways based on Salicylaldehyde Schiff

A novel, easily available colorimetric and fluorescent double-sensor 1 based on Salicylaldehyde bis-Schiff has been investigated in this work. The sensor exhibits highly selective and sensitive recognition toward Cu²⁺ in aqueous solution via a naked eye colour change from colourless to yellow and toward Al³⁺ via a significant fluorescent enhancement in ethanol over a wide range of tested metal ions. This represents the first reported Salicylaldehyde Schiff-based sensor capable of detecting both Cu²⁺ and Al³⁺ using two different modes.     

Fluorescent spongy carbon nanoglobules derived from pineapple juice: A potential sensing probe for specific and selective detection of chromium (VI) ions

Herein, we report, for the first time, the facile, green and one step hydrothermal synthesis of fluorescent spongy carbon nanoglobules (CNG) derived from pineapple juice as a sole carbon source without involving any strong acid treatment. The synthesized CNG not only exhibits hydrophilicity and can remain stable for several weeks but also demonstrates prominent blue color fluorescence under UV light (λ=365 nm). These CNG showed wide range of emission spectra in the visible region depending upon the different excitation wavelengths. The synthesized CNG were characterized in detail in terms of their morphological, structural, optical, compositional and thermal properties using numerous analytical and spectroscopic techniques. For application point of view, the perspective to utilize CNG as fluorescent sensing probe has also been explored with the introduction of various highly toxic metal ions and interestingly, it was observed that the fluorescence intensity of CNG was drastically quenched by chromium (VI) ions with high selectivity over the linear range of concentrations 0–18 µM with stern volmer constant 2.29×10⁴ M⁻¹. Such encouraging results revealed that simply prepared CNG are potential scaffold to fabricate highly sensitive and selective fluorescent sensors for the detection of highly hazardous and life threatening metal ions.     

Surface tuning of halloysite nanotubes with Fe3O4 and 3-D MnO2 nanoflakes for highly selective and sensitive acetone gas sensing

Nanosized M-HNTs-MnO₂ (Magnetic halloysite nanotubes-manganese dioxide) nanocomposite was synthesized by the reduction-precipitation method followed by the hydrothermal process. The existence of MnO₂ nanoflakes on M-HNTs represents 3-D nanostructures without stacking of nanotubes and agglomeration. The sensor-based on M-HNTs-MnO₂ nanocomposites exhibits higher sensor response (R_air/R_gas = 35.6) to 100 ppm of acetone gas at operating temperature (150 °C), with a short response-recovery time (3 s/7 s). The M-HNTs-MnO₂ nanocomposite sensor shows excellent potential to act as a low cost, low-temperature sensor for acetone gas, with high acetone selectivity under high humidity conditions and with the interference of other gases. The high surface to volume ratio, three-dimensional nanostructure, and strong interactions between M-HNTs and MnO₂ nanoflakes are accountable for the improvement of acetone sensing performance. Based on the high acetone selectivity, high stability and fast dynamic response, the M-HNTs and MnO₂ sensor is an extremely appropriate candidate for a low-cost acetone sensor, and the projected approach offers a way to develop gas sensors that can be function at low temperatures for a wide variety of applications.     

A highly sensitive turn-off fluorescent probe based on 2D Eu(III)-MOFs nanosheets for glutathione in vitro and living cells

Glutathione (GSH) is generally used as an effective and sensitive tumor marker because its abnormal levels are associated with high free radical level in tumor. In this work, GSH could be easily detected by a kind of designed Eu-based metal–organic frameworks (Eu-MOFs, named Eu(DTBA)) fluorescent sensor. Due to the “antenna effect” of 4,4′-dithiobenzoic acid (4,4′-DTBA) ligands on Eu³⁺, Eu(DTBA) emits the strong characteristic red light of Eu³⁺ under ultraviolet excitation. Moreover, the emission intensity strongly depends on GSH concentrations. Thus, Eu(DTBA) can serve as a turn-off fluorescent switch of GSH because its framework structure can easily be destroyed by GSH that leads to the fluorescence quenching. Remarkably, during sensing GSH, Eu(DTBA) has shown many appealing performances, such as broad a response window (0–20 mM), fast response (3 min), high sensitivity (LOD = 0.35 µM), and excellent anti-interference ability. The real bioimaging application has demonstrated that the reported Eu(DTBA) can be used as an excellent bioimaging agent to successfully distinguish tumor cells from normal cells in clinical diagnosis.     

基于1,8-萘酰亚胺检测细胞内肼的荧光探针

以对氨基酚和3-溴肉桂酸为原料,以4-溴-1,8-萘酰亚胺为荧光母体设计合成了一例用于检测细胞内肼的荧光探针NH1。该探针能够对肼产生特异性响应。利用1H NMR、MS对NH1进行了结构确证。在体外测试中,探针NH1最大发射波长处（λem=535 nm）的荧光强度随着肼含量的增加而逐渐增强,并且具有良好的线性关系（R2=0.99）,检测限为0.23 μmol/L。该探针有着良好的选择性和抗干扰能力,在广泛pH范围内（4.5~10.5）均能够特异性检测肼。该探针能够染色到细胞内对细胞内的肼进行检测。     

A naphthalimide-rhodamine ratiometric fluorescent probe for Hg based on fluorescence resonance energy transfer

On the basis of fluorescent resonance energy transfer from 1,8-naphthalimide to rhodamine B, a new fluorophore dyads (4) containing rhodamine B and a naphthalimide moiety was synthesized as a ratiometric fluorescent probe for detecting Hg²⁺ with a broad pH range 5.7-11.0. The selective fluorescence response of 4 to Hg²⁺ is due to the Hg²⁺-promoted desulfurization of the thiocarbonyl moiety, leading to the ring-opening of rhodamine B moiety of 4. When 4 was employed at 0.1 μM with the slit size being 20 nm/20 nm, a low level of Hg²⁺ (up to 3 × 10⁻⁸ M) can be detected using the system.     

A highly selective and sensitive fluorescence chemosensor based on optically active polybinaphthyls for Hg

The chiral polymer was synthesized by the polymerization of 4,7-diethynylbenzo[2,1,3]-thiadiazole (M-1) with (R)-6,6′-dibutyl-3,3′-diiodo-2,2′-bis(diethylaminoethoxy)-1,1′-binaphthyl (R-M-1) via Pd-catalyzed Sonogashira reaction. The chiral polymer has orange fluorescence due to the extended π-electronic structure between binaphthyl unit and benzo[2,1,3]thiadiazole (BT) group via ethynyl bridge. The responsive optical properties of the polymer on various metal ions were investigated by fluorescence spectra. The fluorescence of the chiral polymer can produce the pronounced enhancement as high as 1.8-fold upon addition of 1:2 molar ratio of Hg²⁺. Compared with other cations, such as K⁺, Mg²⁺, Pb²⁺, Co²⁺, Ni²⁺, Ag⁺, Cd²⁺, Cu²⁺, Zn²⁺, Mn²⁺ and Fe³⁺, Hg²⁺ can produce the pronounced fluorescence response of the polymer. The result indicates this kind of chiral polybinaphthyls incorporating diethylamino and benzo[2,1,3]thiadiazole (BT) moieties as receptors exhibits highly sensitive and selective behavior for Hg²⁺ detection.